How to Transfer Audio file (.AMR) from One USART to Another USART in STM32F030C8T6

[Tesla DeLorean]

A byte at a time?

[Andrew Neil]

As far as the USARTs are concerned, they neither know nor care anything about "files" or "audio": all they do is send and receive bytes - as @Community member​ suggests.

So is your question:

1. How to send and receive bytes using the STM32F030 USART?
2. How to send a file over an async serial link?

For the latter, I'd suggest you look at something like XModem or YModem.